I am trying to get a better understanding of motor starters. The objective is to create an Excel tool to faster review engineering drawings. Often times, I see NEMA size 2 starters feeding a 5hp motor through a MCP combo starter. The OLR is set correctly but the trip setting of the MCP exceeds the 1100% outlined in article 430 for design B motors.
When my motor is rated X hp, I look up the FLA in T430.250. These currents are not equal to the continuous amps ratings shown in the NEMA starter size table. Starters must be capable of handling the LRC, so I’d always go by hp when looking at a starter. Many corporations have their own standards and require minimum starter sizes. Let me say, the corporate standard requires min. Size 1. This is a problem when trying to feed a 0.5hp dosing pump through a MCP. Did anybody run into similar challenge? It’s hard to program something with so many inconsistencie.
When my motor is rated X hp, I look up the FLA in T430.250. These currents are not equal to the continuous amps ratings shown in the NEMA starter size table. Starters must be capable of handling the LRC, so I’d always go by hp when looking at a starter. Many corporations have their own standards and require minimum starter sizes. Let me say, the corporate standard requires min. Size 1. This is a problem when trying to feed a 0.5hp dosing pump through a MCP. Did anybody run into similar challenge? It’s hard to program something with so many inconsistencie.
